Moe's 8sp build - [email protected]

[HammerHead]

Matt, that was a crazy turn around on getting that truck to the track and run. I bet losing the shaft at 100+ MPH was very interesting.

 

[Pull Ya]

The guy next to him on the track didn't think it was to "interesting" I don't think

Jay

 

[moregrip]

The guy next to him on the track didn't think it was to "interesting" I don't think

Jay

a buddy of mine had his spit out on the dyno and it nearly took us out at the knees not interesting in a good way at least

 

[Hemi450hp]

I felt bad for the SRT8 Challenger I was racing. Partially because I crossed the traps almost a full second before him , and the other because I watched the driveshaft flip end over end, and barely miss hitting his hood. I would have been a man about it and paid for any repair had it hit him, so I'm glad it missed. Neither vehicle suffered any damage aside from needing to replace the driveshaft and pop a few dents out of the muffler.

 

[Kotta390]

I just don't understand the point of the two piece driveshaft on these trucks... You usually don't run into that unless you have a QC or CC truck.

 

[Hemi450hp]

I just don't understand the point of the two piece driveshaft on these trucks... You usually don't run into that unless you have a QC or CC truck.

That is what I will be discussing with DSS when they receive the parts I sent them yesterday. They didnt want to go into too much detail until they had the flanges and dimensions of the stock unit, so I should know more late this week, or early next week.

 

[hemi_loredo03]

Good run Matt. Plenty of ET left on the table. I'm sure you'll be there in less than a couple of months.

 

[Hemi450hp]

Thanks Mike. I'm starting to think that this truck might even see 11.9-12.0 on a stock tq converter.

 

[Dubstep Shep]

I'm gonna get flamed for saying this, but first, no, I don't have links. Second, the trucks I've seen run 11.5x's on motor have all been GM 5.3's and 6.0's. They probably are lighter though, and they don't suffer with transmissions that are touchier than a 13 year old ******* her period.

I actually don't find this too surprising from the LS world... Right now there are people making over 650 to the wheels in a decade old corvette on the stock short block. Just heads, cam, intake, and all the other bolt ons. They're few and far between, but over 600 to the wheels is fairly common for that setup. That's at the wheels too.

Hell, I'm pretty sure the only reason you don't see more of them running fast N/A is because those 5.3L motors are just way too easy to boost.

Case in point, these guys took a junkyard 5.3L, threw on heads, cam, and a turbo and MADE 1,300HP ON A STOCK 160,000 MILE SHORTBLOCK.
Vortec 5.3L - Big Bang - Truckin Magazine

I just don't understand the point of the two piece driveshaft on these trucks... You usually don't run into that unless you have a QC or CC truck.

It's because the joints on the transmission and the axle to the driveshaft are fixed. The driveshaft moves in an arc with the two ends being the transmission and the axle. The axle moves in an arc with the control arms though, and since the control arms are much shorter than the driveshaft, the axle moves in a very different arc from the driveshaft.

There are two common ways around this, but both are two piece driveshafts. Either put a second bearing mount on the driveshaft where the control arms are, or make a variable length driveshaft. We have the latter in our trucks. The S197 mustangs with the straight axle have the former two piece driveshaft design.

 

[Kotta390]

So having a fixed one piece driveshaft won't allow the flexibility it needs to drive around? I've just never heard of a jointed driveshaft on a short bed two door truck.

 

[Hockey39]

Hello Matt, Thanks for working on this very big problem with these driveshafts. On all 8 speed transmission that are 2 doors. Its crazy to think at ... mph that driveshaft will come a parts. Not to mention watch it happen. LOL I would never think about going to the track with out a custom driveshaft and loops install !!! I would 100% keep it the truck under 100 MPH with out the custom driveshaft. You just can't trust it. The driveshafts are the weak link in the drivetrain for sure. It suck when you get your mods done and can't run you truck at the track because of this problem. I never seen this problem coming when I got my R/T . I did a ton of research on this problem after my driveshaft came a part. There is not a guy out there that got there truck over 130 MPH with out there driveshaft coming a part. They put the flex in the middle of this driveshaft instead of in the transmission. Plus they made the driveshaft very weak. The technology in center part of the driveshaft is **** from the factory. I am told there are only two company that can make the center part of the driveshaft stronger. Matt is working with one of them right now. At the end of the day it might turn out that we need to move to a old school two pice driveshaft with a center carrier bearing. If that happens we need a new crossmember. But I am sure Matt will get it figured out for all of us. He alway does. He is the best guy in the country when it comes these Ram trucks. Also he very good to deal with if you want to do any upgrades to your truck. Customer service in this country has gone south in the worst way. It great to know he is there if you have a problem or questions after you get your mods for your truck. Matt please keep us update to date on this big problem. There will be a market for sure on a custom driveshaft and loops for our trucks.

 

[theviking]

Just have to ask, why do the HD trucks run a one-piece ds if it's such a problem?

 

[Hemi450hp]

Just have to ask, why do the HD trucks run a one-piece ds if it's such a problem?

My 2015 crew cab 4wd 8sp also uses a 1 pc aluminum driveshaft. I am not a driveshaft expert though, so I dont have an answer as to why they went this route on the RC 8sp trucks.

DSS received my stock driveshaft parts today, so I am expecting a phone call tomorrow with options on material and pricing. I'll let everyone know what we come up with.

 

[nickpohlaandp]

Just have to ask, why do the HD trucks run a one-piece ds if it's such a problem?

I'm not positive on this one, but I don't think the one piece driveshaft is the problem, it's the two piece driveshaft that fails. I imagine it has a lot to do with phasing and getting that correct in mass production probably isn't easy.

https://www.youtube.com/watch?v=Idk3BVDVHq4

 

[Wild one]

The RCSB 4X4's still use a 1 piece steel shaft,at least my 14 does.

 

[Hemi450hp]

The RCSB 4X4's still use a 1 piece steel shaft,at least my 14 does.

My crew cab 8sp 4wd is 1 piece as well...I'm assuming all the 4wd trucks still use a 1 piece unit.

 

[BackCountryAK]

I've been considering buying a 2016 4x4 crew cab with the 6.4' bed (149" wheelbase) which does have a 2 piece driveshaft. I'm assuming it could have the same failure issues if you go ever go above 100mph?

 

[Hemi450hp]

I've been considering buying a 2016 4x4 crew cab with the 6.4' bed (149" wheelbase) which does have a 2 piece driveshaft. I'm assuming it could have the same failure issues if you go ever go above 100mph?

My 2015 Crew cab 4wd also has the 6'4" bed, and it has a 1 piece driveshaft. I believe only the 2wd crew cab models have a 2pc driveshaft. Even then, I have never seen a 4 door 8sp truck throw a driveshaft...this has only been an issue for the regular cab trucks.

 

[Kotta390]

The RCSB 4X4's still use a 1 piece steel shaft,at least my 14 does.

This maybe a long shot but I wonder if the RcSB 4x4 driveshafts will bolt up to the 2wd transmissions and diff? Surely they are the same or they are entirely different.

 

[Hemi450hp]

This maybe a long shot but I wonder if the RcSB 4x4 driveshafts will bolt up to the 2wd transmissions and diff? Surely they are the same or they are entirely different.

Completely different because the 4wd driveshaft goes into the transfer case, not directly to the back of the transmission.